iBATIS：利用resultMap复合查询

sqlmap文件中：

resultMap=resultMap标签中的id属性

resultClass=类

typeAlias标签定义类别名

---

下面这个sqlmap定义了一个复合查询，从method_table表中查出method_id和rule_type字段，
填充com.xjb.Method类的同名属性；
而ruleList属性是另外一个查询，从rule_table查出多条记录，每条记录对应一个com.xjb.Rule JavaBean类，
然后多条记录作为一个List填充ruleList属性。

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"
    "http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap namespace="Method">
    
    <typeAlias alias="method" type="com.xjb.Method"/>
    <typeAlias alias="rule" type="com.xjb.Rule"/>
    <resultMap class="method" id="methodResultMap">
        <result column="method_id" property="method_id"  />
        <result column="rule_type" property="rule_type"  />
        <result property="ruleList" column="rule_type" select="Method.getRuleListByType" />
    </resultMap>

    <sql id="method_colomns">
        method_id,rule_type
    </sql>


    <select id="getMethodList" parameterClass="map" resultMap="methodResultMap">
        select <include refid="method_colomns"/> from method_table 
            <dynamic prepend="WHERE">
                <isNotEmpty prepend="AND" property="method_id"> method_id = #method_id# </isNotEmpty>
                <isNotEmpty prepend="AND" property="rule_type"> rule_type = #rule_type# </isNotEmpty>
            </dynamic>
        <isNotEmpty prepend="order by " property="_order">
            $_order$
        </isNotEmpty>
        <isNotEmpty prepend="limit " property="_limit">
            #_limit._pstart#,#_limit._psize#
        </isNotEmpty>
    </select>

    <select id="getRuleListByType" parameterClass="String" resultClass="rule">
        select * from rule_table
        <dynamic prepend="WHERE">
            <isNotEmpty prepend="AND" property="value"> rule_type = #value# </isNotEmpty>
        </dynamic>
    </select>
  
</sqlMap>

bean类

package com.xjb;
import java.io.Serializable;
public class Method implements Serializable {
    private static final long serialVersionUID = 000L;

    String method_id;
    String rule_type;
    List<Rule> ruleList;

    public String getMethod_id() {
        return method_id;
    }

    public void setMethod_id(String method_id) {
        this.method_id = method_id;
    }

    public String getRule_type() {
        return rule_type;
    }

    public void setRule_type(String rule_type) {
        this.rule_type = rule_type;
    }

    public List<Rule> getRuleList() {
        return ruleList;
    }

    public void setRuleList(List<Rule> ruleList) {
        this.ruleList = ruleList;
    }

    @Override
    public String toString() {
        return "Method [method_id=" + method_id + ", rule_type=" + rule_type + "]";
    }
}